U.S. patent number 8,230,634 [Application Number 13/105,893] was granted by the patent office on 2012-07-31 for two piece upper receiver for firearms.
Invention is credited to Robert Bruce Davies, Robert Lynch Hogan.
United States Patent |
8,230,634 |
Davies , et al. |
July 31, 2012 |
Two piece upper receiver for firearms
Abstract
A two piece upper receiver for a firearm including a first piece
having a front end, a rear end, a top, and a bottom, the first
piece constructed to operatively carry a bolt carrier and bolt, and
to have a barrel coupled to the front end. The bottom is
constructed to have a lower receiver coupled thereto. The first
piece includes a backbone extending along the top between the front
end and the rear end, the back bone having upwardly directed
indexing surfaces. A second piece overlies the backbone and
includes mating surfaces engaging the indexing surfaces, aligning
the second piece with the first piece. A receiving structure is
opposite the mating surfaces for receiving accessory devices
mounted thereon. Fasteners fixedly attach the second piece to the
first piece to form a complete upper receiver.
Inventors: |
Davies; Robert Bruce (Tempe,
AZ), Hogan; Robert Lynch (Glendale, AZ) |
Family
ID: |
43411854 |
Appl.
No.: |
13/105,893 |
Filed: |
May 12, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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12497048 |
Jul 2, 2009 |
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Current U.S.
Class: |
42/75.02 |
Current CPC
Class: |
F41C
23/16 (20130101); F41G 11/003 (20130101); F41A
3/66 (20130101) |
Current International
Class: |
F41A
21/00 (20060101); F41A 21/48 (20060101) |
Field of
Search: |
;42/75.01,75.02,71.01,85
;89/14.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hayes; Bret
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser.
No. 12/497,048 filed on 2 Jul. 2009. The disclosure of which is
incorporated herein by reference in its entirety.
Claims
The invention claimed is:
1. An upper receiver comprising: a first piece; a backbone, where
the backbone is operatively attached to the first piece, where the
backbone has a first indexing surface and a second indexing
surface, where the backbone has an aperture; a second piece, where
the second piece has a first mating surface and a second mating
surface; a fastener; a barrel nut having an outer surface, a barrel
nut coupling a smooth breech end of a barrel to a front end of the
first piece; and an insert, where the insert fits into the
aperture, where the insert is configured to receive the fastener,
where the second piece is configured to be secured to the first
piece by insertion of the fastener through a portion of the second
piece and into the insert, where the first indexing surface is
configured to contact the first mating surface when the second
piece is secured to the first piece, where the second indexing
surface is configured to contact the second mating surface when the
second piece is secured to the first piece.
2. The upper receiver according to claim 1, where the aperture is
threaded, where the insert configured to fit into the aperture by
screwing into the threads of the aperture.
3. The upper receiver according to claim 1, where the insert is
made from a material different than the first piece.
4. The upper receiver according to claim 1, where the first piece
and the second piece contact surfaces only where the first indexing
surface contacts the first mating surface and where the second
indexing surface contacts the second mating surface.
5. The upper receiver according to claim 1, where the first
indexing surface is angularly opposed to the second indexing
surface by an angle between about 45 degrees and about 135
degrees.
6. The upper receiver according to claim 1, where the second piece
further includes: a receiving structure, where the receiving
structure is configured to receive attachments, where the receiving
structure includes a counter sunk aperture configured to accept the
fastener.
7. The upper receiver according to claim 6, where the receiving
structure is a Picatinny rail.
8. The upper receiver according to claim 7, where the receiving
structure is also part of a handguard.
9. The upper receiver according to claim 8, further comprising: a
wedge block, the wedge block lying between a portion of the second
piece and the barrel nut; and a tensioning system, the tensioning
system forcing the wedge block against the barrel nut.
10. The upper receiver according to claim 9, where the tensioning
system includes: a threaded insert received within an aperture
extending through the second piece; a screw threaded through the
threaded insert and engaging an upper surface of the wedge block,
where the tensioning system is configured to force the wedge block
against the barrel nut when the screw is tightened.
Description
FIELD OF THE INVENTION
This invention relates to firearms. More particularly, the present
invention relates to firearms having an upper receiver coupled to a
lower receiver.
BACKGROUND OF THE INVENTION
In the field of firearms, and specifically AR10, AR15 or M16 type
firearms, various accessories for sighting to improve putting
bullet on target, are employed. These sighting devices must be
securely, rigidly and accurately attached to a firearm. To this
end, firearms include an upper receiver formed of a single piece
and having an upper surface designed to receive various sighting
devices. The upper surface is formed as a rail for receiving and
registering sighting devices. While effective, the typical rail is
a Picatinny rail type that includes cross channels used for
receiving and registering the sighting devices attached thereto.
The formation of cross channels in the upper surface of the upper
receiver thins the material of the upper receiver and can adversely
affect rigidity. The slight flexibility in the upper receiver will
adversely impact accuracy.
It would be highly advantageous, therefore, to remedy the foregoing
and other deficiencies inherent in the prior art.
SUMMARY OF THE INVENTION
Briefly, to achieve the desired objects and advantages of the
instant invention provided is a two piece upper receiver for a
firearm including a barrel. The two piece upper receiver includes a
first piece having a front end, a rear end, a top, and a bottom.
The first piece is constructed to operatively carry a bolt carrier
and bolt, and to have the barrel coupled to the front end. The
bottom is constructed to have a lower receiver coupled thereto. The
first piece includes a backbone extending along the top between the
front end and the rear end and having upwardly directed indexing
surfaces. A second piece overlies the backbone of the first piece
and includes mating surfaces engaging the indexing surfaces
aligning the second piece with the first piece. A receiving
structure is opposite the mating surfaces for receiving accessory
devices mounted thereon. Fasteners fixedly attach the second piece
to the first piece to form a complete upper receiver.
In yet another aspect, the backbone defines the indexing surfaces
which are upwardly directed and angularly opposed. Each of the
angularly opposed indexing surfaces lies on a separate plane, which
planes intersect at a ninety degree angle. Only the mating surfaces
of the second piece engage the backbone of the first piece.
In a further aspect, the second piece has an inner surface and an
outer surface. The second piece overlies and partially encloses the
backbone of the first piece. The inner surface defines the mating
surfaces. The mating surfaces are downwardly directed and angularly
opposed and the outer surface includes the receiving structure for
receiving accessory devices mounted thereon. Only the mating
surfaces engage the backbone at the indexing surfaces. Gaps are
defined between remaining portions of the inner surface and the
backbone.
In yet another aspect of the present invention, a firearm is
provided. The firearm includes a barrel, a lower receiver, and a
two piece upper receiver. The two piece upper receiver includes a
first piece having a front end, a rear end, a top, and a bottom.
The first piece carries a bolt carrier and bolt and the barrel is
coupled to the front end. The lower receiver is coupled to the
bottom of the first piece of the two piece upper receiver. The
first piece includes, as an integral part, a backbone extending
along the top between the front end and the rear end, the back bone
having upwardly directed indexing surfaces, a second piece
overlying the backbone of the first piece and including downwardly
directed mating surfaces engaging the indexing surfaces. The
engaged mating surfaces and indexing surfaces align the second
piece with the first piece. A receiving structure is opposite the
mating surfaces for receiving accessory devices mounted thereon.
Fasteners fixedly attach the second piece to the first piece to
form a complete upper receiver.
Also provided is a firearm including a barrel nut having an outer
surface. The barrel nut couples the barrel to the front end of the
first piece. The second piece extends beyond the front end of the
first piece, and a wedge block is provided having a lower surface
overlying the barrel nut in an abutting relationship, and an upper
surface received adjacent the inner surface of the second piece. A
tensioning system is formed between the wedge block and the second
piece. The tensioning system forces the wedge block against the
barrel nut. In a specific aspect, the tensioning system includes at
least one threaded insert received within an aperture extending
through the second piece from the outer surface to inner surface,
and at least one screw threaded through the threaded insert and
engaging the upper surface of the wedge block, forcing the wedge
block against the barrel nut.
BRIEF DESCRIPTION OF THE DRAWINGS
Specific objects and advantages of the instant invention will
become readily apparent to those skilled in the art from the
following detailed description of a preferred embodiment thereof
taken in conjunction with the drawings, in which:
FIG. 1 is a side view of a firearm with a two piece upper receiver
according to the present invention;
FIG. 2 is a perspective view of a two piece upper receiver
according to the present invention;
FIG. 3 is an exploded perspective view of the two piece upper
receiver of FIG. 2;
FIG. 4 is a top view of the two piece upper receiver of FIG. 2;
FIG. 5 is a sectional side view of the two piece upper receiver
taken along line 5-5 of FIG. 4;
FIG. 6 is a sectional end view of the two piece upper receiver
taken along line 6-6 of FIG. 4; an
FIG. 7 is an enlarged portion of FIG. 6 illustrating the indexing
of the two piece upper receiver pieces.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings in which like reference characters
indicate corresponding elements throughout the several views,
attention is first directed to FIG. 1 which illustrate a firearm
generally designated 10. Firearm 10 includes a lower receiver 12, a
two piece upper receiver 14 carried by lower receiver 12, and a
barrel 16 coupled to two piece upper receiver 14. In the preferred
embodiment, firearm 10 is an auto-loading rifle of the AR10, AR15
or M16 type.
Turning now to FIGS. 2-5, two piece upper receiver 14 for firearm
10 is illustrated. Two piece upper receiver 14 includes a first
piece 20 having a front end 22, a rear end 23, a top 25, and a
bottom 28. First piece 20 is constructed to operatively carry a
bolt carrier and bolt. These elements are not described in detail
as they are conventionally known and used in this application. The
novelty lies in the unique two piece construction of two piece
upper receiver 14. Barrel 16 is coupled to front end 22 with a
barrel nut 30. Lower receiver 12 (as can be seen in FIG. 1) is
coupled to bottom 28 of first piece 20 of two piece upper receiver
14. First piece 20 includes a backbone 32 extending along top 25
between front end 22 and rear end 23. In this embodiment, backbone
32 is an integral part of first piece 20. The term "integral" as
employed herein, refers to a one-piece, common component including
the various elements described. For example, first piece 20 can be
machined or cast from a single piece of material. Backbone 32 has a
length extending substantially from front end 22 to rear end 23,
and has a continuous thickness along the length thereof providing
rigidity and strength to first piece 20. The continuous thickness
of backbone 32 is uncompromised by transversely thinning
discontinuities, such as the transverse channels used in
conventional rail systems. With the thickness undiminished along
the entire length, rigidity is maintained along the entire length,
greatly improving both the strength and accuracy of the
firearm.
Two piece upper receiver 14 further includes a second piece 40.
Second piece 40 includes an inner surface 42 and an outer surface
43, and overlies and partially encloses backbone 32 of first piece
20. In this embodiment, a handguard 45 has been fabricated as an
integral part of second piece 40. In this instance, second piece 40
extends forwardly past forward end 22 of first piece 20. It will be
understood that handguard 45 can be omitted or other handguard
systems can be used with two piece upper receiver 14 of the present
invention. When handguard 45 is present as a portion of second
piece 40 of upper receiver 14, the entire receiver 14 can be
further stabilized with respect to barrel 16 with the use of a
wedge block 33. Wedge block 33 includes a lower surface 34
configured to overlie barrel nut 30 in an abutting relationship,
and an upper surface 35 configured to be received against inner
surface 42 of second piece 40 extending beyond end 33 of first
piece 20. A tensioning system is provided for forcing the wedge
block against the barrel nut. The tensioning system, in this
embodiment, includes threaded inserts 36 and screws 37. Inserts 36
are received within apertures extending entirely through second
piece 40, from outer surface 43 to inner surface 42. Screws 37 are
threaded through each threaded insert 36, and engage upper surface
35 of wedge block 33. In the preferred embodiment, screws 37 extend
into blind apertures 38 formed in upper surface 35 of wedge block
33. As screws 37 are threaded through inserts 36, they force wedge
block 33 against barrel nut 30. The tension system formed between
barrel nut 30, wedge block 33 and second portion 40 greatly
increases the rigidity and thereby increasing accuracy of the
firearm. The bottom of apertures 38 can be lined or otherwise
protected with a hardened material to prevent damage to the wedge
block from screws 37. In the preferred embodiment, wedge block 33
is fabricated from aluminum which is relatively soft and may be
damaged by screws 37. Damage to wedge block 33 is prevented by
placing small steel balls 39 (FIG. 5) in the bottom of apertures
38. The rounded surface of steel balls 39 prevent damage to wedge
block 33, and are in turn, not damaged by screws 37 because of the
hardness of the material used. Additionally, screws 37 can include
cup points which rest over balls 39, distributing the pressure
evenly. While steel is used in this preferred embodiment, it will
be understood that other materials can be used. While a single
screw 37 can be employed for each threaded insert 36, additional
locking screws 41 can be employed. A locking screw 41 is threaded
into threaded insert 36 on top of screw 37, locking it in position
and preventing it from backing out and releasing the tension on
wedge block 33.
With additional reference to FIGS. 6 and 7, it can be seen that
backbone 32 has upwardly directed indexing surfaces 48 and 49
extending along opposing sides thereof. Second piece 40 overlies
and partially encloses backbone 32 of first piece 20 and includes
downwardly directed mating surfaces 52 and 53 engaging (abutting)
indexing surfaces 48 and 49, respectively. Engaged mating surfaces
52 and 53 and indexing surfaces 48 and 49 align second piece 40
with first piece 20. In this embodiment, indexing surfaces 48 and
49 are upwardly directed and angularly opposed and mating surfaces
52 and 53 are downwardly directed and angularly opposed. Each of
angularly opposed indexing surfaces 48 and 49 lies in a separate
plane, which planes preferably intersect at a ninety degree angle.
Thus, in this embodiment, two indexing surfaces 48 and 49 are
provided which surfaces are angled at a preferred 45 degree angle
with reference to a horizontal or vertical axis A. For purposes of
this description, it will be understood that the term "angularly
opposed" defines indexing surfaces that have intersecting planes,
and that those intersecting planes of the indexing surfaces
intersect at an angle greater than 0.degree. and less than
180.degree., and preferably between 45.degree. and 135.degree..
This also applies to the mating surfaces which engage the indexing
surfaces. While in this embodiment indexing surfaces 48 and 49 are
two continuous surfaces extending from proximate front end 22 to
proximate rear end 23, additional surfaces could be used, and they
could be discontinuous (e.g. the continuous surfaces broken into a
plurality of separate surfaces).
A receiving structure 55 is provided opposite mating surfaces 52
and 53 (on the outer surface) for receiving accessory devices such
as sighting devices, and the like, mounted thereon. In this
embodiment, receiving structure 55 is in the form of a Picatinny
rail (MIL-1913) type system although other systems can be used.
Also, as illustrated, receiving structure 55 extends the length of
second piece 40 and handguard 45 which can be provided as a part of
and extend from the end of second piece 40.
In order to provide the extreme accuracy of two piece upper
receiver 14 of the present invention, indexing surfaces 48 and 49
and mating surfaces 52 and 53 are employed. To insure proper
engagement (abutting relationship) between these surfaces, and
thereby insure accurate and highly repeatable alignment, only
mating surfaces 52 and 53 engage backbone 32 at indexing surfaces
48 and 49. Gaps 50 are defined between remaining portions of inner
surface 42 and backbone 32 to insure this engagement with no
distortions or interferences. Gaps 50 can be large or small and
have substantially any shape, as long as only mating surfaces 52
and 53, and indexing surfaces 48 and 49 contact one another. Thus
it will be understood that top 25 of first piece 20 and inner
surface of second piece 40 can have a variety of shapes and
configurations. By accurately and repeatably aligning first piece
20 and second piece 40 of two piece upper receiver 14, any
accessory devices (e.g. optical sights, projection devices, etc.)
carried by receiving structure 55 remain as originally aligned even
after disassembly and reassembly.
Fasteners are employed to fixedly attach second piece 40 to first
piece 20 to form complete upper receiver 14. Fasteners in this
embodiment include screws 60 which pass through second piece 40 and
threadably engage first piece 20. In this embodiment, apertures are
formed in the top surface of backbone 32 and threaded inserts 62
are fit therein to provide tighter tolerances. Screws 60 are
counter sunk in receiving structure 55 to prevent interference with
accessory devices attached thereto, and threadably engage threaded
inserts 62. Screws 60 are positioned down through the top of second
piece 40 and first piece 20 to pull second piece 40 downwardly onto
first piece 20, aligning in a repeatable manner first piece 20 with
second piece 40 by the engagement between mating surfaces 52 and
53, and indexing surfaces 48 and 49.
Various changes and modifications to the embodiments herein chosen
for purposes of illustration will readily occur to those skilled in
the art. To the extent that such modifications and variations do
not depart from the spirit of the invention, they are intended to
be included within the scope thereof which is assessed only by a
fair interpretation of the following claims.
Having fully described the invention in such clear and concise
terms as to enable those skilled in the art to understand and
practice the same, the invention claimed is:
* * * * *